PURPOSE: To measure accurately temperatures in the left and the right of an oral or in the left, the right, and the center of the oral cavity by producing a part of a supporting body, which incorporates a temperature sensor, into a shape approximating the row of teeth or the gum of a person to be examined, and keeping relative positions of measuring points constant.

CONSTITUTION: Plural supporting bodies 2 where temperature sensors 1 such as thermocouples, thermistors, thermomodules, or the like are attached to tips are produced into one body so that they can be inserted easily into the oral cavity. A connection wire 3 is connected to a temperature display device 4. A metallic plate which has holes, grooves, or the like punched and is made easy to bend or a wire net is attached to a stabilizing plate 4.1 consisting of a deformable plastic or rubber plate, and this stabilizing plate 4.1 receives a pressure (p) together with a protection tube 2 and is pressed to the inside wall of the lower jaw and is stabilized in this position.